The legacy keyboard driver is implemented in various files in hw/xfree86/common,
which leaves a lot of OS-specific code in the common directory. Also, the
keyboard driver is hardwired into the initialization sequence, giving a lot of
special cases.
A worthwhile cleanup, which will remove ~4300 lines of code from the X server.
The new keyboard driver "kbd" provides a feature equivalent replacement, which
is contained in hw/xfree86/input/keyboard plus os-specific parts. It's not
currently supported on all platforms, but by marking it as deprecated in the
next release (6.7 + 1) and removing it in the release after that, should allow
those platforms to catch up.

Kristian, this was discussed on today's release wranglers call, and it was
decided that it was okay to apply the "depricate old keyboard driver and disable
compilation by default" patch. Please go ahead.
Also, when you have applied the patch move this bug over to block the release
notes bug (#999).